Energizers for aromatic triamino developing agents and suppression of proximity development in azine color developers



Patented Dec. 30, 1952 ENERGIZERS FOR AROMATIC TRIAMINO DEVELOPING AGENTS AND SUPPRESSION F PROXIMITY DEVELOPMENT IN AZINE COLOR DEVELOPERS Robert C. Gunther, Galesburg, Ill., assignor to General Aniline & Film Corporation, New York, N. Y., a corporation of Delaware No Drawing. Application March 21, 1950,

Serial No. 151,052

12 Claims. 1

The present invention relates to energizers for aromatic triamino developing agents and to a method of suppressing proximity development in the processing of multilayer color film to azine dyestufi images while employing Z/i-diaminoanilines for color development.

It is known that azine dyestufi images inexposed silver halide emulsions are produced by color developing silver halide emulsions with 2,4- diamino-aniline developing agents inthe presence of color formers. The procedure of this process is described in United States Patent 2,486,440, granted on November 1, 1949.

The azine dyes produced in this way have unusual stability and superior spectral characteristics, particularly when compared with the quinonimine or azomethine dyes produced with developers of the p-phenylenediamine type.

Despite the many recognized advantages of this new class of color developers, they possess two disadvantages which provide a somewhat serious problem in the use of the azine method. The first disadvantage occurs in the development of multilayer film and is manifested by a loss of color rendition in the azine images formed in such material.

Such loss of color rendition has been found to be attributable to a phenomenon peculiar to the aforementioned azine processing which is characterized hereintas proximity development. The following explanation of such phenomeno will serve to give a better understanding of; the objects of the present invention.

As is known, the conventional-materialemployed at the present time in color photography is an integral tripack consisting essentially of three superimposed silver halide emulsionlayers, the bottom layer being sensitized to red, the middle layer to green, and the top layer. to blue. When such a trip'ack is exposed, the red densities of the picture are recorded in thebottorn layer, the green densities in themiddle layer, and the. blue densities in the top layer. According to customary practice, the image formed; in the respective layers is complimentary in color tothe light rays for which the particular layer is sensitized.

One of the best modes of constructing such tripacks involves the utilization in each of the three silver halide emulsion layers of a .color former which is rendered non-diffusing in the emulsions. Where such tripacks are of the reversible type, they are processed by developing first in a black and white developer, and finally in a colorforming developer.

2 Inthe color development of such a tripack with a ZA-diamino-aniline, the color developer reduces in any one layer the silver halide remaining after the first development and is itself oxidized to "an active state capable of coupling with the color former present in that layer to form a positive dye image. Consequently, in any one layer the amount of dye produced will be a function of the amount of residual silver halide in that layer and the resulting dye will be formed imagewisa- Thus, in each of the three layers of the tripack, one of the primary color densities (blue in the top layer, green in the middle layer, .and red in the bottom layer) is accurately recorded in the form of a positive complimentary dye image.

The coupling reaction between the migratory oxidized developer and the immobile color former in each layer is normally rapid so that the oxidized developer travels only a very short distance before encountering the color former molecule and coupling therewith. It often happens, however, that some dye may be produced in a par ticular layer by the coupling of a color former in that layer with an oxidized developermolecule that originated not in that particular layerbut in one of the adjacent layers. oxidized developer molecule originating in the red-sensitive layer may escape from this layer without coupling and migrate to the green-sensitive layer to couple with the color former molecule in that layer. As a result, there will be produced in the green-sensitive layer a certain amount of magenta dye which records not the green densities of the original picture, but red densities which should have been confined to the bottom or red-sensitive layer. This migration of oxidized developer from one layer to an adjacent layer is the phenomenon known as proximity development.

The other disadvantage also occurs in the development of multilayer film and is manifested by the inability of the first (black and white) developing agent to reduce the slightly activated silver in the highlight or white portions of the processed film As a consequence, the highligh ts of the processed film are not clean, also thecolor rendition in the lighter densities is, somewhat poor. The non-reduction of the slightly activated silver is presumably due to the sluggishness of the first developer.

I have now discovered that this tendency toward proximity development, in the processing of tripacks by theazine method whileusing. 2,4" diamino-anilinefor. color development, can be eliminated, o greatly suppressed by utilizing in Typically, an

' the azine color forming developer, in the concentration of 0.5 to 10 grams per liter, of a reaction product obtained by condensing a 2,4-diaminoaniline with a lower alkyl a-ketocarboxylic acid or with a lower alkyl aldehyde.

The condensation products are mild black and white developers and are more rapid in their initial reduction of exposed silver halide than the 2,4-diamino-aniline developers. They develop the residual silver halide, present in the highlights, which was not earlier developed due to the sluggishness of the first developer. The slight development in other than highlight density has little noticeable effect on the final image. This development takes place without the formation of color and thus leads to the production of clean whites and brilliant highlights.

The condensation product in the aforestated concentration range energizes the 2,4-diaminoaniline developing agent so that the slightly activated silver is actually reduced. It appears that the reaction product reacts with the slightly activated silver and as a result yields improved color rendition and clean whites due to the development of the slightly activated or residual silver. 7 .When the condensation products are employed in the (reversal) azine developer, the color separation and, consequently, the brilliance of the color images especially the whites are also markedly improved over those obtained, but free from such a reaction product.

The energizing of the 2,4-diamino-aniline developing agent and the suppression of proximity development in the azine procedure while utilizing 2,4-diamino-anilines for color development constitute the purpose and principal object of the present invention.

Other objects and advantages will appear from the following description.

The 2,4-diamino-anilines which are employed as the color developers and for the preparation of the condensation product, by treatment with a lower alkyl a-ketocarboxylic acid or with lower alkyl aldehyde, are of the type described in the aforementioned Patent No. 2,486,440 and characterized by the following formulae:

Y NH R3 and IITRIR:

wherein R1 is hydrogen or an aliphatic radical, such as alkyl, 1. e., methyl, ethyl, propyl, butyl, amyl, and the like, carboxyalkyl, such as carboxymethyl, carboxyethyl, carboxybutyl, and the like, hydroxyalkyl, such as hydroxymethyl, hydroxyethyl, hydroxypropyl, hydroxybutyl, and the like, sulfoalkyl, such as sulfomethyl, sulfopropyl, sulfobytyl, and the like, R2 is aliphatic as above, or an aromatic radical, such as aryl, i. e., phenyl, naphthyl, and the like, carboxyaryl, i. e., carboxyphenyl, carboxynaphthyl, and the like, sulfoaryl, such as sulfophenyl, sulionaphthyl, and the like, alkoxyaryl, such as methoxyphenyl, methoxynaphthyl, ethoxyphenyl, butyroxyphenyl, and the like, alkylaryl, such as toluyl, ethylphenyl, propylphenyl, and the like, heterocyclic, such as Z-pyridyl, 2-piperidyl, Z-indolyl, z-quinolyl, and the like, R3 is an aromatic or aliphatic radical as illustrated above, Q represents the atoms necessary to complete a six-membered isocyclic ring system, such as benzo and the like, and Z and Y are hydrogen, sulfo, or carboxy.

The lower alkyl a-ketocarboxylic acids and lower alkyl aldehydes, which are treated with the 2,4-diamino-aniline to form the condensation product are those of the following formulae:

R4-CHO and Rs-COCOOH wherein R4 is hydrogen or a lower alkyl, such as methyl, ethyl, propyl, butyl, isobutyl, amyl, and the like, and R5 is a lower alkyl of the same value as R4.

Specific examples of such lower alkyl a-ketocarboxylic acids and aldehydes are:

Pyruvic acid 3-methyl-pyruvic acid c-ethyl-pyruvic acid B-propyl-pyruvic acid fi-isopropyl-pyruvic acid and the like Formaldehyde Acetaldehyde Propionaldehyde Butyraldehyde Isobutyraldehyde, etc.

4 (c-sulfoethylarrm Color formers to be used with the aforementioned developers to give yellow azine dye images are also described in application Serial No. 101,913, filed June 28, 1949, now Patent No. 2,570,116. These compounds are typified by the fact that they are open chain ketomethylene compounds. Examples of such compounds are:

Acetoacetanilide N-l-naphthylacetoacetamide N,N'ethylenebisacetoacetamide p,p'bi-o-acetoacetaniside N-2naphthylbenzoylacetamide p,p'-bi-acetoacetanilide a,a-terephthaloylbis(3-chloro 4,6 dimethoxyacetanilide) a-benzoylacetanilide.

Preferably, the color formers utilized contain a group rendering them non-migratory in the emulsion. Examples of such compounds are:

v 2- (m-benzoylacetamidcphenyl)F 1, octadecyleiir benzimidazolesulfonic. acid.

3,3."-ureylenebis 5 p benzoylacetamidobenzamide-benzenesulfonic acid 2ep-benzoylacetamidobenzamidee 6 -stearoy1ami;-

no-p-toluenesulfonic acid 2-(p-benzoylacetamidophenyl) l octadecyl-5- benzimidazolesulfonic acid p-cyanoacetyl-3-octadecenylsuccinalic acid.

Color formers capable of producing magenta dyestuii images. are also described in application Serial No. 101,913, filed June 28, 1949, as well as in, application Serial No. 793,533, filed December 23, 1947:, now. Patent No. 2,524,741. Preferably,

these color; formers are 6i-.halogen8-.hydroxyquinolines, and particularly those which are non- .migratory in the emulsions. Examples of the latter type, compounds are:

Color formers for the cyan image are also described in application Serial No. 101,913 and in United States Patent 2,445,252, granted July 13,

1948. Preferably, these color formers are aryl-J- acid derivatives, particularly those containing a group rendering the color former non-migratory in the emulsion. Examples of the latter cornpounds-are:

Dodecyl urethane of fi-sulfoethyl-J-acid Tetradecyl urethane of p-anisyl-J-acid 2-hexadecyl urethane of phenyl-J-acid 4 -stearoylaminophenyleJ-acid, and the like.

The reaction products of ZA-diamino-anilines with the lower alkyl a-ketocarboxylic acid or aldehyde utilized in accordance with the present invention are prepared by first suspending one part of a ZA-diamino-aniline in a mixture of 2.5 parts of a. lower boiling alcohol, such as methyl, ethyl, or isoprcpyl alcohol, in 1 part of 3N hydroohloric acid solution. To this mixture 3 parts ofeither the acid or aldehyde are added and the whole warmed on a steam bath to id-50 C. until the solution of the ZA-diamino-aniline is completed. Thisusually takes about 10 to minutes. The clear, amber-colored solution is treated with decolorizing carbon and filtered. The hot filtrate is diluted with 3 parts of alcohol and cooled in an ice bath. The product, which separates as pink to colorless crystals, is collected on a Buchnei' funnel, washed with alcohol, and dried. The yield of the final product is in the range of 60-70%.

Although the exact composition of the reaction product has not been definitely established, it is believed to be ofthe dihydrobenzimidazole type. The formation of such a compound might be postulated on the basis of the iollowingreaction while utilizing 4 (B hydroxyethylamino) 6- phenylamino-metanilic acid as the 2, l-diaminoaniline and (1) 3-methyl-pyruvic acid as the lower alkyl ketocarboxylic. acid and; ('2) pro.- pionaldehyde as. the aldehyde:

(1) lTTHGuHs GHaCHzCHO --r --NHCH2CH1OH' NHCaHs 1120 --N-CHzCHz QH $112011; I Ct -t CHaCHsCOOOOH --s NHCHzCHzOH HOaS . CO2 H2O -NHCH2CH2OH' HNCH The reaction products, prepared in accordance scribed in my application Serial No. 151,053, filed on March 21, 1958, are added to azine color developers that are used for the development by diffusion Where the color forming component'is in solution in the color developer, or development of emulsions containing non-diffusing color form ers, and development by either reversal or negative processing procedures.

The following examples describe in detail methods for accomplishing the above objects, but it is to be understood that they are inserted merely for purposes of illustration and are not to be construed as limiting the scope of the invention.

Example I A a" x 5" sheet of an integral 'tlfi aclg composed of a red-sensitive bottom layer containing a non-diffusing azine cyan dy forming color component, a green-sensitive middle layer containin a non-diffusing azine magenta dye forming color component, and a blue-sensitive top layer containing a non-diffusing azine yellow dye forming color component, was exposed and the latent image developed for 10 minutes at 68 F. in a black and white developer of the following composition:

p-Monomethylamino phenol sulfate g 2 Sodium sulfite; -g 20 Hydroquinone "g", 4 Sodium carbonate g Sodium thiocyanate 'g 5 Potassium bromide g 4 Water to make cc 1000 The developed film was shortstopped for 3 minutes in a 3% aqueous solution of acetic acid, re-exposed and color developed for 15 minutes at 68 F. in a developer of the following composition:

7 4-(fi-hydroxyethylamino) -6a1lyl aminometanilic acid l g 6 Sodium carbonate, monohydrate g 40 Sodium sulfite g 60 Potassium bromide g 7.5 Pyridine g 12 Reaction product from l-(B-hydroxyethylamino 6 phenylamino metanil- V ic acid and pyruvic acid g 3 Water to make cc 1000 After development, the color developed film was bleached in a ferricyanide bleach bath, fixed in an acid hardening hypo bath, and bathed for a few minutes in a bicarbonate-formaldehyde hardening bath.

After drying, the film showed much better color rendition and cleaner whites. In fact, the blues, greens, and reds of the film were substantially more brilliant than those in the same film developed in the same color developer'but not containing the reaction product from 4- methylamino-6phenylamino-metanilic acid and pyruvic acid.

Erample II A developer solution of the following composition was prepared:

4 (c hydroxyethylamino) 6 phenylamino-metanilic acid; g 5 Sodium carbonate, monohydrate g 50 Sodium sulfite g 50 Potassium bromide g 4.5 Benzylamine g Reaction product from 4 (p hydroxyethylamino 6 phenylamino metanilic acid and fi-ethyl-pyruvic acid g 2.5 Water to make ec 1000 An integral tripack composed of a red-sensitive bottom layer containing a cyan color former,

SOsH a green-sensitive middle layer containing a magenta color former,

H l and a blue-sensitive top layer containing a yel- .low color former,

H 000 011200 Net-O0 0 NH- NC 0 0111135 SOaH was exposed, the latent image developed in a black and white developer'as in Example I, reexposed, and then developed for minutes in the above developer solution.

After development, the film was washed,

8 bleached in ferricyanide bleach, and fixed in an acid hardening hypo solution.

As a result, there was obtained a multicolor positive (cyan dye in bottom, magenta in middle, and yellow in top) of exceptional clarity and brilliance, with unusually clean whites.

Example III An integral tripack with a bottom layer composed of ,a red-sensitive emulsion containing phenyl-J acid-octadecyl urethane, a middle layer composed of a green-sensitive emulsion containing 2 stearoylamino-6-(8-hydroxycinchoninoylalnino)-toluene-l-sulfonic acid, and a top layer composed of a blue-sensitive emulsion containing 2 (4 benzoylacetaminophenyl) l octadecyl-5-benzimidazole sulfonic acid was exposed and the latent image developed in a black and white developer, re-exposed, and the residual silver halide developed in a solution of the following composition:

-(e hydroxyethylamino) 6 phenylamino-metanilic acid g 5 Sodium carbonate, monohydrate g 40 Sodium sulfite g 60 Potassium bromide g 5 Pyridine g 16' Benzylamine g 1 Reaction product frBH i EIIQeEiJIHQB-E phenylamino-metanilic acid and propionaldehyde g 4 Water to make cc 1000 After development, the film was washed, bleached in a ferricyanide bleach, fixed in an acid hardening hypo, and bathed in a bicarbonate-formaldehyde hardening bath. There was thus obtained a film in which the blues, greens, and reds were substantially more brilliant than those in the same film developed in the same color developer but not containing the reaction product from 4-methylamino-6-phenylamino metanilic acid and propionaldehyde.

Example IV Example II was repeated with the exception that the reaction product from l-(fi-hydroxyethylamino)-6-phenylamino-metanilic acid and ,B-ethyl-pyruvie acid was replaced by the same quantity of the reaction product from d-methylamino-6-phenylamino-metanilic acid and acetaldehyde.

Example V R4CHO and Rs-COCOOH with elimination of water, wherein R4 is selected from the class consisting of hydrogen and lower alkyl, and R5 is lower alkyl.

2. A developer according to claim 1, in which the condensation reaction product is that from 4- (B-hydroxyethylamino) -6-phenyl-amino metanilic acid and pyruvic acid.

3. A developer according to claim 1, in which the condensation reaction product is that from 4- B-hydroxyethylamino) 6 phenylamino metaanilic acid and acetaldehyde.

4. A developer according to claim 1, in which the condensation reaction product is that from 4-methylamino 6 phenylamino-metanilic acid and propionaldehyde.

5. A developer according to claim 1, in which the condensation reaction product is that from 4 methylamino-6-phenylamino-metanilic acid and B-ethyl-pyruvic acid.

6. A developer according to claim 1, in which the condensation reaction product is that from i-(fi-hydroxyethylamino) -6-phenylamino metanilic acid and 3-methyl-pyruvic acid.

7. In the process of producing subtractively colored azine dye images in a tripack consisting of three superimposed silver halide emulsion layers containing color formers capable of coupling with the oxidation products of a 2,4-diaminoaniline developing agent to form azine dye images by exposing and developing the same with a color developer containing as the effective developing agent 2,4-diamino-aniline, the improvement wherein said developer additionally contains a product obtained by the condensation reaction of 2,4-diamino-aniline with a compound selected from the class consisting of the following formulae:

R4-CHO- and Rs-COCOOH with the elimination of water wherein R4 is selected from the class consisting of hydrogen and lower alkyl, and R5 is lower alkyl.

8. The process as defined in claim 7, wherein the condensation reaction product contained in the color developer is that from -(fi-hydroxyethyiamino)-6-phenylamino-metanilic acid and pyruvic acid.

9. The process as defined in claim '7, wherein the condensation reaction product contained in the color developer is that from 4-(p-hydroxyethylamino)-6-phenylamino-metanilic acid and acetaldehyde.

10. The process as defined in claim 7, wherein the condensation reaction product contained in the color developer is that from 4-methylamino- G-phenyIamino-metanilic acid and propionaldehyde.

11. The process as defined in claim 7, wherein the condensation reaction product contained in the color developer is that from 4-methy1- amino-6-phenylamino-metanilic acid and B- ethyl-pyruvic acid.

12. The process as defined in claim '7, wherein the condensation reaction product contained in the color developer is that from 4((3-hydroxyethylamino)-6-phenylamino-metanilic acid and 3- methyl-pyruvic acid.

ROBERT C. GUNTHER.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,440,954 Jennings May 4, 1948 2,486,440 Schmidt Nov. 1, 1949 

1. A PHOTOGRAPHIC DEVELOPER COMPRISING A 2,4DIAMINO-ANILINE AND A PRODUCT OBTAINED BY THE CONDENSATION REACTION OF A 2,4-DIAMINO-ANILINE WITH A COMPOUND SELECTED FROM THE CLASS CONSISTING OF THE FOLLOWING FORMULAE:
 7. IN THE PROCESS OF PRODUCING SUBTRACTIVELY COLORED AZINE DYE IMAGES IN A TRIPACK CONSISTING OF THREE SUPERIMPOSED SILVER HALIDE EMULSION LAYERS CONTAINING COOR FORMERS CAPABLE OF COUPLING WITH THE OXIDATION PRODUCTS OF A 2,4-DIAMINOANILINE DEVELOPING AGENT TO FORM AZINE DYE IMAGES BY EXPOSING AND DEVELOPING THE SAME WITH A COLOR DEVELOPER CONTAINING AS THE EFFECTIVE DEVELOPING AGENT 2,4-DIAMINO-ANILINE, THE IMPROVEMENT WHEREIN SAID DEVELOPER ADDITONALLY CONTAINS A PRODUCT OBTAINED BY THE CONDENSATION REACTON OF 2,4-DIAMINO-ANILINE WITH A COMPOUND SELECTED FROM THE CLASS CONSISTING OF THE FOLLOWING FORMULAE; 